As the core technology of the next generation transport networks, the Optical Transport Network (OTN) not only has abundant Operation Administration and Maintenance (OAM), strong Tandem Connection Monitor (TCM) and out-band Forward Error Correction (FEC) capability, but also can perform flexible scheduling and management of large volume service, and has increasingly become a major technology of the backbone transport networks.
With the rapid development of types of data service, operators hope the OTN to provide better support to data of multiple services, such as client signals of Ethernet, fiber channel (FC) and Synchronous Digital Hierarchy (SDH), etc.
Conventionally, in the related art, transmission of different types of client signals are realized by using Optical Channel Data Unit-k (ODUk), where k=1, 2, 3, 4. At the transmitting end, a client signal to be transmitted is mapped into the ODUk, an overhead is added to the ODUk to form an Optical Channel Transport Unit-k (OTUk) frame, and the OTUk frame is transferred to the OTN for transmission, where k=1, 2, 3, 4.
However, the inventor finds that, the rates of four ODUk (k=1, 2, 3, 4) are predetermined, with the rate of ODU1 being 2.5G, the rate of ODU2 being 10G, the rate of ODU3 being 40G, and the rate of ODU4 being 112G. In mapping the client signal to be transmitted to the ODUk at the transmitting end, the rate of the ODUk and the rate of the client signal to be transmitted cannot be matched accurately. Thus the bandwidth of OTN transport channel is seriously wasted. Meanwhile, for multiple client signals, the transmitting end has to bundle these multiple client signals together and map them into a single ODUk, which is inconvenient for the OTN to manage each client signal.